JPH07203603A - Apparatus and method for controlling speed of electric rolling stock - Google Patents

Abstract

PURPOSE: To automatically control the speed for safe drive by providing an auxiliary electric brake function by a means for comparing the magnitude of rotational signals per minute and a current signal with a value supplied from an input section and a maximum current value, and then driving a motor. CONSTITUTION: Based on data from an input section 40, number-of-revolutions signals SE1 per minute from a number-of-revolutions detecting section 70 and a current signal from a current detecting section 100 which detects the amount of current flowing to ground, a control section 50 executes a control routine. After number-of-revolutions signals SE1 per minute detected by sensors 70 and 100 and a current signal SE2 are inputted to set values, set values A, B, C, and D are inputted and the SE1 values are compared with the B value. If the SE1 values are greater than the B value, then the SE2 value is compared with the D value. If the SE2 is smaller, that is judged as non-steady-state running and a signal for normal and reverse conversion for actuating electric braking is added to the base of a transistor 90. As a result, safe running is automatically accomplished.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to speed control of an electric vehicle, and more specifically, it automatically controls the speed of a vehicle that is running abnormally such as overspeed to ensure safe operation. The present invention relates to a speed control device and a control method thereof.

[0002]

2. Description of the Related Art Conventional electric vehicles do not have a speed limiting system, and thus have a problem in safety due to traveling on a sloping ground or traveling at high speed.

Further, since there is no auxiliary braking system which complements the durability of the braking system, the mechanical braking system is easily worn.

[0004]

SUMMARY OF THE INVENTION Therefore, the present invention automatically controls the traveling speed to safely drive the vehicle when traveling abnormally such as a process on a sloping ground due to the driver's immature driving or the like. An object of the present invention is to provide a speed control device for an electric vehicle and a control method therefor.

Another object of the present invention is to provide a speed control device and a control method therefor capable of improving the durability of a mechanical braking system.

[0006]

SUMMARY OF THE INVENTION A speed control device of the present invention is a speed control device for an electric vehicle having a mechanical brake and a running brake, and an electric brake demand value related to the number of revolutions per minute of the motor. An input unit for setting a maximum speed value, an electric brake limit value and a maximum current value of the motor, and a rotation speed detection for detecting a current rotation speed of the motor and generating a rotation speed signal per minute. Unit, a current sensing unit that detects a current amount of current flowing through the motor and generates a current signal, and a magnitude of the rotation signal and the current signal per minute according to the value and the maximum current value provided from the input unit. And a control unit for applying a predetermined control signal by means for driving the motor, and having an electric brake function assisted by the control function by the mechanical brake. It is characterized.

A speed control device of the present invention is a speed control method for an electric vehicle having a brake and a traveling motor,
An electric brake demand value, a maximum speed value and an electric brake limit value, a maximum current value of the motor, a current rotation speed of the motor per minute, and a current amount related to the rotation speed of the motor per minute; A first step of inputting a signal; a second step of comparing the current number of revolutions per minute and the current amount of current to the maximum speed value and the maximum current value, respectively; and the current number of revolutions per minute. If the number is greater than the maximum speed value and the current amount of current is less than the maximum current value, after reversing the rotation direction of the motor, the duty value of the gate driver is set to the current number of revolutions per minute. A third step of setting a value according to the electric brake limit value and comparing the current number of revolutions per minute with the electric brake limit value, the number of revolutions per minute being the electric brake limit. Is characterized in that it comprises a fourth step of driving the mechanical brake is larger than.

The speed control device of the present invention is a speed control method for an electric vehicle having a brake and a traveling motor,
Input the electric brake demand value, the maximum speed value, the electric brake limit value, the brake switch signal, the current rotation speed of the motor per minute, and the current amount of current related to the rotation speed of the motor per minute. The first process,
When the brake switch signal is in the ON state, a second step of comparing the current number of revolutions per minute and the current amount of current with the electric brake required value and the maximum current value, respectively, and The number of revolutions per hit is greater than the number of revolutions per minute corresponding to the electric brake request value,
When the current amount of current is larger than the maximum current value,
After the duty value of the gate driver is set to 0, the third step of reversing the rotation direction of the motor and the duty value of the gate driver related to the speed by the electric brake are set to the current number of revolutions per minute and the current. It is characterized in that a fourth step of setting the quantity and the value associated with the electric brake limit value and the maximum current value is continuously provided.

[0009]

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a circuit diagram of an electric vehicle to which the speed control device of the present invention is applied. The direction switch 10, the brake switch 20, the accelerator pedal 30, the input unit 40, the current sensing unit 100, and the rotation speed sensing. The signals and the like provided by the unit 70 are connected so as to be provided to the control unit 50 composed of a microcomputer, and the signals and the like provided by the control unit 50 are the warning unit 60, the motor 120, and Driving transistor 90, forward / reverse converter 80
And as provided to the forced braking circuit 110.

When the driver sets the speed limiting data suitable for safe driving through the input unit 40, the control unit executes a predetermined speed control routine to output predetermined processing result data for wheel driving (or running). The transistor 90 that drives the motor 120 is provided.

At this time, the control unit 50 provides the data set by the driver provided by the input unit 40 and the rotation speed sensing unit 70 for detecting the revolutions per minute (RPM) of the motor 120. Revolution speed signal (SE1) per minute, and motor drive transistor 90
Current sensing unit 1 for detecting the amount of current flowing to the ground through the
The control signal is added to the base of the motor driving transistor 90 so that the vehicle travels properly by performing a control routine that is a speed control program based on the current signal (SE2) provided by the vehicle. The rotation of the drive motor 120 is adjusted.

In addition, the control unit 50 outputs a predetermined control signal to the warning unit 60 when it determines that the vehicle is operating abnormally according to the execution of the speed control routine, and the warning unit 60 is operated. Generates a warning sound to let the driver know that the vehicle is operating abnormally. At this time, the driver can forcibly stop the vehicle through the brake switch 20, but when a brake stop signal is input to the control unit by the brake switch 20, the control unit 50 causes the forced brake circuit 110 to operate. A stop control signal is output so that the wheels are mechanically stopped.

On the other hand, the speed control routine executed by the controller 50 will be described below with reference to FIGS. 2 (A), 2 (B) and 3.

FIG. 2A is a graph showing the relationship between the revolutions per minute signal (SE1) of the rotation sensing unit 70 and the revolutions per minute of the motor 120 corresponding to the traveling speed of the electric vehicle. 2 (B) is a current signal (SE2) of the current detector 100 with respect to the amount of current flowing through the motor 120.
It is a figure showing the relationship of.

In FIG. 2A, the set value A of RPM
(Or A ') is a value (hereinafter referred to as "electric brake required value") that requires the operation of the electric auxiliary brake when the driver controls the brake, and B (or B') is on a sloping land or the like. Maximum speed value required by the driver when the vehicle is accelerated (hereinafter referred to as "maximum speed value"),
C (or C ') is the RPM value (hereinafter "RPM value") that warns the driver and forcibly activates the mechanical brake when the RPM continues to increase without being decelerated during continuous electric auxiliary brake control. Electric brake limit value ")
Is.

Further, in FIG. 2B, D (or D ')
Is the maximum current value (hereinafter referred to as "maximum current value") when the driver intentionally drives at high speed, and E (or E ') is the minimum current value (that maintains the backboard capacity of the electric vehicle ( Hereinafter referred to as "minimum current value").

The control unit 50 inputs the revolutions per minute signal (SE1) and the current signal (SE2) detected by the sensors 70 and 100 to the values thus set, and thereafter,
The set values (A, B, C, D) are input (step S31), and first, the SE1 value and the B value are compared (step S32).

That is, in step S32, if the SE1 value is smaller than the B value, the comparison step is continued based on the data which is continuously input, and if the SE1 value is larger than the B value, the process proceeds to step S33. Step S33
Then, the SE2 value is compared with the D value. If the SE2 value is large, it is determined that the vehicle is running normally and the comparison operation based on the new input is continued. The motor 120 is used to judge and operate the electric brake.
The signal for forward / backward conversion is added to the base of the transistor 90.

In this way, when the electric auxiliary brake operation is started, in step S35, the duty value Dg of the gate driver related to the speed of the electric brake braking is detected and the detected RPM value and C The value Dg1 by f (SE1, C) which is a function of the value is substituted. While the braking of the electric brake continues,
In step S36, the SE1 value provided from the rotation speed sensor 70 is again compared with the C value. If the SE1 value is larger than the C value, it is determined that the speed cannot be reduced as the braking of the electric auxiliary brake, and the control unit 50 forcibly operates the mechanical brake in step S39. A control signal is provided to the compulsory braking circuit 110, and a control signal is also sent to the warning unit 60 to warn the driver to proceed to the next comparison step (S40).

In the comparison step (S40), the comparison step (S3)
If the SE1 value is larger than the C value, the step (S39) is continued, and if the SE1 value is larger than the C value, the step S37 is continued.

In step S37, the SE1 value is compared with the B value. If the SE1 value is large, the process proceeds to step S38, in which Dg is changed to Dgtt (where t is the minimum duty ratio of the traveling driver). Yes), the process proceeds to the forward / backward conversion step (S34), and if not, the process proceeds to step (S32). In this way, the control unit 50 performs a speed control routine to perform a function of reducing the abnormal speed to a stable speed. That is, even if the inclination angle is unstable or the acceleration condition is unstable because the vehicle speed is fixed to the B value, the maximum vehicle speed that ensures stability can be maintained.

On the other hand, the operation sequence of the auxiliary brake will be described with reference to FIG.

In step S41, the control unit 50 controls the brake switch signal (S
E) and SE1, SE2, A, B and C values are input.

Steps based on the input data (from S42 to S
At 44), it is determined whether SB is turned on, the SE1 value is compared with the A value, and the SE2 value is compared with the D value.

As described above, when SB is turned on, the SE1 value is larger than the A value, and the SE2 value is larger than the D value, the process proceeds to step S45 to set Dg to 0 (zero).

Next, in step S46, the motor is subjected to forward / reverse conversion, and then in step S47, Dg is changed to Dg2.
= (SE1, SE2, A, D). Where Dg
2 is a function of SE1, SE2, A and D.

Next, in step S48, it is determined whether SB is turned on, and if it is turned on, the process proceeds to step S49 to compare whether SE1 is larger than the A value.

At this time, if SE1 is larger than the A value, the process proceeds to step S50 to set Dg to Dg + t,
Proceed to step S47.

In such an auxiliary brake operation routine, the driver first receives a set value to determine whether or not the brake switch is turned on, and when the brake switch is turned on, the vehicle speed is required by the electric auxiliary brake. It is determined whether the speed (A value) is reached.

When the vehicle speed is higher than the A value, and when the motor current exceeds the minimum motor current value for maintaining the backboard capacity of the vehicle, the auxiliary brake operation control is executed to reduce the motor current.

According to such an auxiliary brake operation routine, it is possible to start on a sloping ground without slipping, and it is possible to increase the durability of the mechanical brake by simultaneously operating the electric auxiliary brakes. is there.

[0033]

[Brief description of drawings]

FIG. 1 is a circuit diagram of an electric vehicle to which a speed control device of the present invention is applied.

2 is a graph showing a state of a revolutions per minute (RPM) signal generated from the revolutions sensing unit of FIG. 1 according to the present invention. FIG. 2B is a graph showing a state of a current signal generated from the current sensing unit of FIG. 1 according to the present invention.

FIG. 3 is a flowchart showing a speed control process according to the present invention.

FIG. 4 is a flowchart showing an electric auxiliary brake actuation process in the speed control method according to the present invention.

[Explanation of symbols]

 40 input unit 50 control unit 70 rotational speed sensing unit 100 current sensing unit 120 motor

Claims (10)

[Claims] 1. A speed control device for an electric vehicle having a mechanical brake and a running brake, wherein an electric brake demand value, a maximum speed value, an electric brake limit value, and an electric brake limit value related to the number of revolutions per minute of the motor are provided. The input unit for setting the maximum current value, the rotation speed per minute detection unit for detecting the current rotation speed per minute of the motor and generating a rotation speed signal per minute, and the current amount of current flowing through the motor are displayed. A current sensing unit for detecting and generating a current signal, and means for driving the motor by comparing the magnitude of the rotation signal and the current signal per minute with the value and the maximum current value provided from the input unit, respectively. 2. A speed control device, comprising a control unit for applying a predetermined control signal according to 1., and having an electric brake function assisted by the control function by the mechanical brake. 2. The speed control according to claim 1, wherein the means for driving the motor comprises a transistor for adjusting a current amount of the motor in response to a control signal supplied from the controller. apparatus. 3. A speed control method for an electric vehicle having a brake and a running motor, wherein an electric brake demand value related to the number of revolutions per minute of the motor, a maximum speed value and an electric brake limit value, and the motor. A first step of inputting a signal relating to a maximum current value, a current number of revolutions per minute of the motor, and a current amount of current; and The second step of comparing with the maximum current value, and the rotation direction of the motor when the current number of revolutions per minute is larger than the maximum speed value and the current amount of current is smaller than the maximum current value. After reversing, the third step of setting the duty value of the gate driver to a value according to the current number of revolutions per minute and the electric brake limit value, and the current number of revolutions per minute A speed control method comprising a fourth step of comparing a number to the electric brake limit value and driving a mechanical brake when the number of revolutions per minute is greater than the electric brake limit value. 4. The speed control method according to claim 3, wherein the mechanical brake is driven in the fourth step, and after the warning signal is generated, the fourth step is repeated. 5. In the fourth step, if the current rotation speed per minute is smaller than the electric brake limit value, the current rotation speed per minute is compared with the maximum speed value, and then the When the current number of revolutions per minute is higher than the maximum speed value, the method further comprises the step of reversing the rotation direction of the motor after adding the minimum duty value of the traveling driver to the current duty value. The speed control method according to claim 4. 6. A speed control method for an electric vehicle having a brake and a traveling motor, wherein an electric brake demand value, a maximum speed value, an electric brake limit value, and a brake switch signal related to the number of revolutions per minute of the motor. A first step of inputting a signal relating to the current number of revolutions per minute of the motor and a current amount of current; and, if the brake switch signal is in an ON state, the current number of revolutions per minute and the current amount of current are A second step of respectively comparing the electric brake demand value and the maximum current value with each other, and the current rotation speed per minute is higher than the rotation speed per minute corresponding to the electric brake demand value, and the current current A third step of reversing the rotation direction of the motor after setting the duty value of the gate driver to 0 when the amount is larger than the maximum current value; A fourth step of continuously setting the duty value of the gate driver related to the speed of the electric brake to a value associated with the current number of revolutions per minute and the current amount of current and the electric brake limit value and the maximum current value is continuously performed. A method for controlling speed, comprising: 7. A fifth step of comparing the current number of revolutions per minute to the electric brake required value when the brake switch signal is in an ON state, and the current number of revolutions per minute is equal to the electric brake demand value. If it is larger than the required brake value, a sixth step of advancing to the fourth step after adding the minimum duty ratio of the traveling driver to the current duty value is further provided after the fourth step. The speed control method according to claim 6. 8. The speed control method according to claim 7, wherein, in the fifth step, when the brake switch signal is in an off state, the step proceeds to the second step. 9. The speed control method according to claim 7, wherein, in the sixth step, when the current number of revolutions per minute is smaller than the electric brake required value, the step proceeds to the second step. 10. The second step until the brake switch signal is on, the current number of revolutions per minute is greater than the electric brake required value, and the current amount of current is greater than the maximum current value. 7. The speed control method according to claim 6, wherein is repeatedly performed.